FIELD: The subject invention is in the field of harvesting and milling trees, particularly the smaller diameter trees such as those harvested in the process of thinning trees on tree farms. The supply of wood is diminishing while the need for it is increasing and therefore it has become economically feasible and more important to use the smaller trees and to use them as efficiently as possible in terms of using as much of the tree as feasible while improving the quality of the end product called lumber.
In conventional milling of the smaller diameter trees, the trunks are cut into logs having lengths of 8, 10, 12, 16, 20 and 24 feet, depending on the diameters of the tapered trunks at their bases. The logs are then sawed to produce rough sawn lumber and there is considerable wastage, particularly when the end product is geometrically perfect rough sawn lumber. Significant reduction of wastage and end product improvement are achieved using techniques disclosed in U.S. Pat. No. 5,896,723, issued to the inventor of the subject invention. These techniques involve sawing the logs so that they have two parallel flat sides or a basically rectangular or square cross section shape with radiused corners called wanes. These logs are then sawn in half lengthwise and the halves reassembled with the outer surfaces that are parallel to the saw-cut glued together. The reassembled logs are then sawed in half lengthwise again with the cut perpendicular to the outer surfaces, yielding two boards flat on three sides and having an indentation in the center of the fourth side. This product has high quality because the wood originally at the center of the log is at its exterior where its superior strength is most effective. Also, U.S. Pat. No. 5,896,723 explains in considerable detail the fabrication of a variety of wooden structural units made from this product. In the procedures disclosed in patent '723 harvested logs are used in their harvested condition and lengths. This incurs some wastage because, since the trees are tapered and the product is not, the material removed in eliminating the taper is wasted.
The simultaneous increasing need for wood and decreasing supply make it important to further increase the efficiency of producing, from smaller diameter trees, the wood products described above by decreasing wastage and further improving the quality of the end products. Accordingly, the objective of the subject invention is to provide a method for more efficient use of smaller diameter trees, decreasing wastage and further improving quality of the end products.